Fikearm choke mounting



Ma ch 10, 1964 F. A. PACHMAYR ETAL 3 123,929

FIREARM CHOKE MOUNTING mam Filed Jan. 16, 1962 cNmM/ m f;

United States Patent Ofi ice 3,123,929 Patented Mar. 10, 1964 3,123,929 FIREARM CHUKE MGUNTING rank A. Paehmayr, Los Angeles, and Walter R. Nass, Escondido, Calif., assignors to Paehmayr Gun Works, inc Los Angeles, Calif., a corporation of California Filed .lau. l6, 1%2, Ser. No. 166,534 12 Claims. (Cl. 42-79) This invention has to do generally with improved means for mounting choke devices to the muzzle ends of firearms, i.e. shotguns, in a manner permitting the choke device to be positioned and maintained in accurately predetermined angular relation to the barrel.

For various reasons known to those familiar with the art, it may be desirable to affix the choke device to the gun barrel so that the choke axis may have angular departure, say as much as plus or minus 2 /2 degrees, from the barrel axis. Usually the problem is that of providing a practical and accurate means for so attaching the choke device to a normal straight surface muzzle end of the gun barrel.

The invention contemplates a new and improved mounting employing the general combination of a ring applicable to the barrel surface and held against movement therefrom, a tubular choke body applicable about the ring, and means inside the body for variably clamping the body to the ring in angularly variable relation to the gun barrel.

To facilitate application to and removal from the barrel, the ring is made in split form, and to permit the stated variability of the choke angularly with secure holding at a selected angle, the ring surface is tapered forwardly and rearwardly to engage against correspondingly shaped seat and clamping annuli inside the barrel. Preferably, the ring is given convex surface curvature, with the ring-engaged forward seat annulus correspondingly curved. The clamping annulus threaded into the end of the barrel similarly has an internal bearing surface curved in accordance with the ring surface curvature, thus to assure maximum surface inter-engagement be tween the ring, seat and clamping annuli in all angular positions of adjustment of the choke body.

This invention has various additional features and ob jects, such as modes of securing the ring against end displacement from the gun barrel, all of which will be understood more fully from the following detailed de scription of illustrative embodiments of the invention shown by the accompanying drawing, in which:

FIG. 1 is a view showing a typical and illustrative form of choke device applied to the muzzle end of a gun barrel;

FIG. 2 is a cross sectional View showing, according to one form of the invention, the angularly variable interlock between the choke body and gun barrel;

FIG. 3 is a view showing the split retaining ring in elevation;

FIG. 4 is a cross section on line 44- of FIG. 3; and

FIG. 5 is a view similar to FlG. 2, showing a variational form of the invention.

FIG. 1 illustrates generally a tubular choke device applied in pre-determined angular relation to the muzzle end of a shot gun barrel 11. Other than with respect to the later described variable interlock between the barrel and rear end of the choke device 10, the invention is not concerned with the details of the latter, and accordingly it will be understood that the invention contemplates the use of suitable or known form and structure of choke device which, as is commonly known, functions to control the shot pattern emanating from the choke device. Accordingly, it will sutiice to describe the latter typically as being in tubular form, comprising a rear section 12 adapted for mounting to the gun barrel and having gas escape slots 13, and a forward section 14 rotatably adjustable in known manner relative to the rear section 12 to control the shot pattern.

Referring to FIG. 2, the invention contemplates a novel form of mounting generally indicated at 15, whereby the choke device 10 may be rigidly held to the gun barrel at any position of axial angularity relative thereto, within for example a range of plus or minus 1 /2 as illustrated by the broken lines 16 and 16a. The desirability for angular variance between the choke device and barrel is to compensate for the corrections necessary between the barrel and choke control alignment, caused by installing the choke control; also to compensate for differences in sight height between the original barrel and choke control, as the choke control generally raises the front sight, after installation, from original height. This changes the sighting plane, causing the gun to shoot low at various distances. Being able to correct the alignment between the choke control and barrel by angular variance enables the installer to correct the striking point of impact of the shot charge.

The mounting assembly 15 is shown to comprise a split ring 17, having sections 17a and 17b as shown in FIG. 3, applicable to a cylindrical end surface of the barrel 11, the outside surface of the ring being tapered forwardly and rearwardly, respectively at 13 and 19, preferably by shaping the ring surface with symmetrical convexity substantially as illustrated. According to the form of the invention shown in FIG. 2, the ring is held against endwise movement from the barrel by engagement against an accurately symmetrically enlarged diameter end surface of the barrel produced preferably by the illustrated outward expansion or flaring at 20. As an alternative method of retaining the ring 17 to the barrel, and in this instance against movement in either axial direction, the ring sections may be seated in an annular recess 21 in the barrel surface, see FIG. 5, so that the sections are engageable against stop shoulders 22 and 23 defining the recess. Whenever desirable, the inner surface of the ring sections may contain seals 24.

Section 12 of the choke device is shown to be internally threaded at 25 to receive a forward seat ring 26 which is screwed into fixed position against shoulder 27. The internal surface of the seat 26 has concave taper and curvature in correspondence with the shape of the forward ring surface 18.

The threaded end of the choke body 12 also receives a threaded clamping ring 28 having a wrench head 29 and a threaded shank 3'9 with an internal surface 32 engageable against and having concave curvature corresponding to the rear surface 19 of the clamping ring. Thus the split ring 17 together with the engaging and correspondingly shaped seat and clamping ring surfaces 26 and 32, form a joint in the nature of a limited range ball swivel, allowance of adjustability within the desired range being permitted by appropriate clearance at 31 between the clamp ring and gun barrel surface.

In mounting the choke device to the barrel, the locking ring 2.8 is first slipped onto the barrel, and before flaring of its end at 2% in the case of FIG. 2, after which the barrel end may be enlarged if that mode of attachment is used. The seat ring 26 having been screwed to seated position within the choke body, the latter is then brought about the ball seat ring 17 and clamping ring 28 tightened into engaging position. After the choke device it is adjusted to predetermined angularity relative to the barrel, the clamping ring 23 may be firmly tightened against the seat ring to fixedly lock the choke in its set position.

We claim:

1. The combination comprising a firearm barrel, a choke device including a tubular body applied about the end of the barrel, a first ring applied to the barrel inside the body and having outer forward and rearward surfaces tapered axially of the ring respectively forwardly and rearwardly of the barrel, and means mounting said body to the ring in angular-1y variable relation of the body axis to the barrel axis, said means comprising a second ring threaded into the end of the body to surround and bear against the rearward surface of said first ring, said second ring being adjustably slideable longitudinally of the barrel on the first ring surface and being tightenable to hold the body in axially adjusted relation to the barrel.

2. The combination of claim 1, in which said outer surface of the first ring has convex curvature in cross. section axially of the barrel.

3. The combination of claim 1, in which said first ring is diametrically split.

4. The combination of claim 1, including an annular seat within the body and engaged by the forward surface of said first ring.

5. The combination of claim 4, in which said seat is threaded into the body.

6. The combination of claim 1, comprising also means presenting an annular shoulder on the barrel to hold said first ring against movement off the barrel.

7. The combination of claim 6, in which said shoulder is formed by a radially expanded end portion of the barrel.

3. The combination of claim 7, in which said shoulder is formed by an annular recess in the barrel.

9. The combination comprising a firearm barrel, a tubular choke device including a tubular body applied about the end of the barrel, a split ring applied to the barrel and having an outer surface curved convexly axially of the ring, a seat ring threaded into the body and having an inner surface engaged by and curved substantially in accordance with the forward portion of said outer surface of the split ring, and a clamping ring threaded into the body and having an inner surface engaged by and curved substantially in accordance with the rearward portion of said outer surface of the split ring, said clamping ring serving to adjustably hold said body in angularly Variable relation to the barrel.

10. A choke device comprising a ring appliccble to a firearm barrel and having an outer surface curved convexly in cross section axially of the barrel, a tubular body adapted to telescope over the ring, forward and rear annular members in the body engageable against and in surrounding relation the forward and rear portions of said ring convex surface to hold the body in angularly variable relation to the ring axis, said rear member being threaded into the end of the body to have clamping engagement with the ring.

11. A choke device according to claim 10, in which said ring is diametrically split and the inner surfaces of said members are curved concavely and axially of the members in substantial conformance with the ring surface curvature.

12. A choke device according to claim 10, in which said forward member is threaded to predetermined fixed position in the body.

References Cited in the file of this patent UNITED STATES PATENTS 

1. THE COMBINATION COMPRISING A FIREARM BARREL, A CHOKE DEVICE INCLUDING A TUBULAR BODY APPLIED ABOUT THE END OF THE BARREL, A FIRST RING APPLIED TO THE BARREL INSIDE THE BODY AND HAVING OUTER FORWARD AND REARWARD SURFACES TAPERED AXIALLY OF THE RING RESPECTIVELY FORWARDLY AND REARWARDLY OF THE BARREL, AND MEANS MOUNTING SAID BODY TO THE RING IN ANGULARLY VARIABLE RELATION OF THE BODY AXIS 